473,395 Members | 1,678 Online
Bytes | Software Development & Data Engineering Community
Post Job

Home Posts Topics Members FAQ

Join Bytes to post your question to a community of 473,395 software developers and data experts.

Relationships for cascading tables

Hi
I am new to database design. I am building a database to handle the paperwork for boat companies maintenance. I have made a series of tables using foreign keys to interlock the tables. I think ive done it wrong as i have relationships from the first table to all subsequent tables. See pic. Is it enough to just link one table to the next without all these extra relationships?
Regards
Russ
Attached Images
File Type: jpg tableRelations.jpg (69.0 KB, 156 views)
Jul 13 '19 #1

✓ answered by twinnyfo

Russ,

It depends. Based upon your relationships, it says that your Vessels, Equipment, Tasks and Task Done all have a company associated with them. This is not "inherently" incorrect, as this may be true. But, typically, we don't associate a company with a Task or a Task Done.

By the way, are you working in MS Access or MySQL? I'm happy to move this thread to MS Access if so. Being new to DB design, it might be quite a leap to jump directly into MySQL, but stranger things have happened....

Sounds like there may be more structurally unsound in your DB than just how many other tables one table is related to. You may want to review this article on Database Normalization first before you continue.

2 2299
twinnyfo
3,653 Expert Mod 2GB
Russ,

It depends. Based upon your relationships, it says that your Vessels, Equipment, Tasks and Task Done all have a company associated with them. This is not "inherently" incorrect, as this may be true. But, typically, we don't associate a company with a Task or a Task Done.

By the way, are you working in MS Access or MySQL? I'm happy to move this thread to MS Access if so. Being new to DB design, it might be quite a leap to jump directly into MySQL, but stranger things have happened....

Sounds like there may be more structurally unsound in your DB than just how many other tables one table is related to. You may want to review this article on Database Normalization first before you continue.
Jul 15 '19 #2
Thanks, Twinny and yes I'm learning them both. I need to use MySQL because I want it to be web-based, so people can enter and retrieve data via their own devices. The company is included so I could alow separate businesses to use it, but restrict data based on a company login. I am using access to test my tables as its easier to build forms and querys there for me at this stage. I am then creating a similar set up in MySQL. I have cleaned up some of the excess fields in my second DB.
Russ
Jul 16 '19 #3

Sign in to post your reply or Sign up for a free account.

Similar topics

4
by: gaffar | last post by:
Sir, I am developing an application in vb.net and the backend database is ms-access. i have created ms-access databse and tables and assigned primary keys to the tables through the vb.net...
1
by: Paradigm | last post by:
I am new to MYSQL (been working with Access for years and now seen the light). One thing I cannot get sorted is how to create relationships between my SQL tables. Can someone point me in the right...
1
by: Ealadi | last post by:
In an access database I have two tables: "Students" and "Postnr" The first table has various students' information including fields labelled "Postnr." and "City". Another table has only two...
2
by: runners4bush | last post by:
In general will I see any query performance gains? More of a DB2 guy myself. Regards Phil
1
by: missboom | last post by:
Hi there, this one has been annoying me and i know it *should* be simple, im creating a database that has users, and every user will have an administrator in charge of them, so one user will...
2
by: missboom | last post by:
I am creating a db for users in a company, each user uses different programes (a choice of 5) some may use one and some may use many, each program has different settings and in the db has a table...
0
hirak1984
by: hirak1984 | last post by:
hi, i have to get the relationship among various primary and foreign keys in different tables in a schema. e.g==>the output will be like........ ...... is the primary key of ..........table,...
2
by: morleyc | last post by:
Hi, i've started a c# project using MS compact SQL as a datasource. I am able to add tables in the server explorer and columns in these tables, but how can i add relationships between tables...
1
desklamp
by: desklamp | last post by:
Access 2003 on Win2K The tables involved: an IP address table, tblIP, where basic IP address information is stored: IP, WHOIS, reverse DNS name, etc. an event IP table, tblIPEvent, where...
2
by: Roger | last post by:
I've moved all my tables to sql server2005 and I've created the appropriate relationships now I create links to two such tables that have a relationship into ms- acess97 but when I add the two...
0
by: ryjfgjl | last post by:
If we have dozens or hundreds of excel to import into the database, if we use the excel import function provided by database editors such as navicat, it will be extremely tedious and time-consuming...
0
by: ryjfgjl | last post by:
In our work, we often receive Excel tables with data in the same format. If we want to analyze these data, it can be difficult to analyze them because the data is spread across multiple Excel files...
0
by: emmanuelkatto | last post by:
Hi All, I am Emmanuel katto from Uganda. I want to ask what challenges you've faced while migrating a website to cloud. Please let me know. Thanks! Emmanuel
1
by: nemocccc | last post by:
hello, everyone, I want to develop a software for my android phone for daily needs, any suggestions?
1
by: Sonnysonu | last post by:
This is the data of csv file 1 2 3 1 2 3 1 2 3 1 2 3 2 3 2 3 3 the lengths should be different i have to store the data by column-wise with in the specific length. suppose the i have to...
0
by: Hystou | last post by:
There are some requirements for setting up RAID: 1. The motherboard and BIOS support RAID configuration. 2. The motherboard has 2 or more available SATA protocol SSD/HDD slots (including MSATA, M.2...
0
by: Hystou | last post by:
Most computers default to English, but sometimes we require a different language, especially when relocating. Forgot to request a specific language before your computer shipped? No problem! You can...
0
Oralloy
by: Oralloy | last post by:
Hello folks, I am unable to find appropriate documentation on the type promotion of bit-fields when using the generalised comparison operator "<=>". The problem is that using the GNU compilers,...
0
by: Hystou | last post by:
Overview: Windows 11 and 10 have less user interface control over operating system update behaviour than previous versions of Windows. In Windows 11 and 10, there is no way to turn off the Windows...

By using Bytes.com and it's services, you agree to our Privacy Policy and Terms of Use.

To disable or enable advertisements and analytics tracking please visit the manage ads & tracking page.